Signal chime



Patented a. a, 1935 PATENT OFFICE SIGNAL CHIME Robert D. Karnell, Cleveland, Ohio, assignor to Kai-mac, Inc., Cleveland, Ohio, a corporation of Ohio Application June 6, 1932, Serial No. 615,589

3 Claims.

This invention relates to signal devices such as musical chimes for door bell signals and the like. The invention has for its objects the provision of a device which possesses the characteristics of compactness in structure, economy of manufacture, clarity of tone and adaptability for installation either as a single or multiple chime structure.

Referring to the drawing, Fig. 1 is a general view of my device in elevation, portions being broken away to more clearly disclose the construction; while Fig. 2 is a sectional view showing the striking plunger in the striking position.

The chime device embodying my invention is adapted to be mounted upon a wall and to have the operating structure embedded within the wall. To this end, I employ a vertically disposed chime bar ID, a tubular resonator ll, preferably closed at the ends, and which has an opening l2 disposed in front of the bar and between the points of the support I3 and I4, respectively. Such supports preferably comprise posts l5 which connect the resonator with an escutcheon plate 4| which is adapted to be attached to the wall by any securing means. The chime bar may be supported on the posts I5 also preferably resting on the upper post, but not touching the lower one. The movement of the chime bar on the post I5 is limited on one side by the rubber bumper l9 and on the other by felt pad 32.

The striking mechanism is also adapted to be mounted upon the same support, as the bar and resonator, and the preferred arrangement comprises a casing l6 which is fastened to the back of the plate and embedded within the wall. The casing carries a field magnet I! and a striking plunger l8. The plunger is slidahly mounted in the passageway within the magnet and is adapted when the magnet is energized to pass through an opening 2| and to strike the bar Ill.

A spring 22 normally holds the plunger in retracted position and operates when the magnet is energized to pass through an opening 2i and to strike the bar H]. A spring 22 normally holds the plunger in retracted position and operates when the magnet is energized to allow the plunger to strike the bar and then to draw it away from the bar instantaneously so as to allow the bar to vibrate freely. Suitable leads 25 and 26 extend from the coil to the binding posts 21 and 28, respectively, on the casing for connecting the coil in an electric circuit.

I have found that clarity and richness of tone can be readily obtained in a relatively small device, as for instance with a bar six inches in length, if the distance between the top of the bar and the top of the post i3 is approximately onefourth the length of the bar, and if the distance between the bottom of the bar and the center of the opening through which the post I 4 passes, is approximately one-fourth the length of the bar. I have also found that the lower post should be out of contact with the walls of the lower opening 30, and that the posts should be covered with a suitable dampening material such as rubber 3|.

To obtain compactness of structure in the striking mechanism and economy of manufacture thereof, I utilize a one-piece member for the pole piece and connect the coil, pole piece and plate 4| together by a sleeve 36, which is disposed in the center of the coil and acts as the guideway for the movable plunger. The ends of the sleeve may be swaged over as at 3'! like an eyelet to hold the parts in proper assembled relationship.

The striking plunger has a padded head and has such length and diameter that normally it projects beyond the rearward end of the coil and is held against a felt abutment 42 by the spring 22 acting in compression. Preferably the spring 25 is a helical member adapted to embrace the plunger. When the coil circuit is closed the magnetic field causes the plunger to strike the chime bar at the same time compressing the spring, which in turn serves to retract the plunger. I 30 prefer to arrange the spring in a converging helix which may be doubled inwardly upon itself, as at 33, in Fig. 2. The spring thus acts in tension to quickly retract the plunger after striking the bar. This aids in procuring clarity of tone. 3

My device lends itself readily to the arrangement of a plurality of chimes, each giving a different tone, and provided with means for striking them simultaneously or in series, thus giving a pleasing musical effect.

I claim:

1. In a device of the class described, a unitary structure comprising in combination a support, two posts extending laterally from the support 45 and in vertical alignment, a chime bar suspended freely from the upper post, the chime bar having a lower opening through which the lower post passes without touching the bar, the distance from the top of the bar to the suspension point and the distance from the bottom of the bar to the center of the bottom opening each being substantially equal to one-fourth the length of the bar, a resonator supported from the ends of the posts, there being an opening in the resonator opposite the mid section of the bar, and electromagnetically actuated means positioned on the side of the support opposite the bar and comprising a coil and a plunger for striking the bar at substantially the mid-point thereof.

2. In a device of the character described, the

combination with a vertically extending esciitcheon plate, having an opening therethrough, of a tubular resonator, means to support said resonator in a vertical position parallel with and spaced apart from said plate, a chime bar parallel with and disposed between said plate and said resonator, said chime bar being supported solely by the means which supports said resonator, electromagnetic means including a plunger adapted to project through the opening in the escutcheon plate and strike said chime bar, said last named means being supported by said plate on the side thereof opposite said chime.

3. In a device or the class described, the combination with a support, of a chime bar suspended vertically therefrom, a tubular resonator rigidly secured to the support in parallel spaced relation to the bar. a solenoid winding carried by the support and having an opening therethrough, a core within the opening and adapted to strike the bar, a conical spring having its base mounted over the opening through which the core extends, and its opposite end secured to the core, and wherein the normal extended length oi. said spring is less than the throw of the plunger, whereby the energization of said solenoid operates the spring in 15 compression until said spring doubles on itself. ROBERT D. KARNEIL. 

